Oblig noob questions (in New players)

Hi, oh wait, pizza! yumm, grab some... so, its my 3rd night here and while i've read a lot i can't pretend to know that i'd actually know what I'm reading. so, pizza.

1- right now i figure i'm in the xp generating business..
2- so i made a fireball mage
3- and leveled him to 40k hp, 20 str, 8100 dex, 7700 fb

what i'm wondering, besides 1-3 being ok, is, if i'm doing the right thing

4- just giving my money to the blacksmith for upgrades
5- not saving for auction stuff i cant appraise/dont understand
6- always going for a 100% bonus in fights
7- acting like i'll re-invest into something like 'a strategy' later.

8- plus my power graph looks pretty weird. wtf?

so maybe you wise one's could offer some insights,

9- yes, by the numbers; tuna. the pizza had tuna. can you believe that?

thanks all!

a single fireball mage ideally should train 1 hp for every 2 fireball levels. dex is not needed.

things you may want is a helm of clearsight, a tattoo, amulet of invisibility, spellboosters/displacement boots. if you cant buy them you cna score some in rentals im sure.